Fatty material stabilized against oxidation and stabilizers therefor



UNITED STATES 3P FATTY MATERIAL STABILIZED AGAINST OXIDATION ANDSTABILIZER'SHHERE- *FOR .Noel H. Knhrt, Rochesterg N. ,Y., assignortoEastman Kodak Company, Rochester, N. -Y., a corporation of New JerseyIENT OFFICE No Drawing. Application Ja nuary'1'1,i.1952,

Serial N0.'-266;106

10 Claims. (Cl. 991'63) 1 This invention relates tostabilized fattycomject to oxidation, including both solid fats and positions and tostabilizers for fatty material t y oils, a d pa t cu a ly the f ttymaterials normally subject to oxidation. consisting predominantly offatty triglycerides Fatty materials, such assolid fats, fatt oils rfat-forming fatty acids containing unsatuand fatty acids, andparticularly the fatty ma- 5 rated components and hence subject tooxi'daterials having unsaturated components are nort The a ty ly id si cudeanimal'fats mally subject to oxidation and resultant oxidasuch aslard, tallow and the like, andvegetable tive rancidity due, at least inpart, to the deoils such as cottonseed oil, soybean oil, peanutyelopment of peroxides in such fatty materials. oil, coconut oil, cornoil and the like, Whether since the fatty materials such as the animalhy r s n or p t ly hy r n and fats and the vegetable oils, whetherunhydroincluding the animal and vegetable shortenings.

:genated or partially hydrogenated, are widely Th f y ci i l ny f therum r mixed usedas cooking fats, salad oils, shortenings and unsaturatedfatty ac ds as yp fi d y o acid the like, the fatty materials must bestabilized and linoleic acid. against objectionable oxidation, Thestabilizer composition embodying this'in- It is-accordingly an object ofthis invention vention comprises'asolution of glycineand p to providenew fattycompositions characterized D o c acid. i a hydroxy polyalky e ode 98118! by improved stability against deleterious per- Of a fa m a tyacid. Any of the well oxide formation and resultant oxidative ranknownhydroxy polyoxyalkyl ne ester 'of fatcidity. 2 forming fatty acids canbe employed in prac- It is a further objectof theinvention to .protioingthis invention D Vided such esters have vide nevr stabilizercompositions suitable for ina melting point not substantially hi herthan corporation in fatty materials normally subject 100 C., and thoseesters having a melt ng point to oxidation and effective tostabilizesuchfatty below 0 C. are preferred. The hydr y p materials againstobjectionable oxidation. xy ky ene est rs employ d in pr ct n th It isalso an object of the invention to provide invention are obtained inaccordance Withknown new stabilized compositionsconsistingpredomipractice by co ensing-a fat-forming fatty acid nantlyof fatty triglycerides. With from 5 to 60 'molar proportions of anAnother object of the invention is :to stabilize kyl ne oxide or by r acin a fa y a id with edible fatty materials against development ,ofalkylene oxide polyme The 'l o y y y e objectionable oxidative rancidityunder normal de a ives are des ably emp oyed i practicin storage onditins, this invention although other oxyalkylene de- Another object of theinvention is .toprovide rivatives such a 1;2propylene oxide or L13-improved animal fat or vegetable oil-composiopyl ne oxide deriv t ve cabe emp oy dif tions, including both unhydrogenated and pardesired. Theester can be a hydrOXy p0 y0Xytially hydrogenated compositions. alkyleneester of "any of the well-known fat- Another object of theinvention is'tostabilize forming fatty acid with those fatty acids havfatty materialagainst oxidationwithout impairing at least 12 carbon atoms in the fattyacid ment of the desirable physical and chemical molecule beingvpreferred, as typified by lauric properties of such fatty material. 40acid, stearic acid, oleic acid, ,palmitic acidand. Other objects will beapparent from the dethe like. Good results are obtained over a widescription and claims which follow. range of esters as, for example, withhydroxy- These and. other objects are attained linsac- 8-cxyethylenemonostearate and hydroxy-j40- cordance with this invention byincorporating oxyethylene monostearate, the number in each in .a fattymaterial normally subject to oxidacase referring to the molarproportionsof ethyltion, a solution of glycine and phosphoric-acid ene oxide .foreach molar proportion of fatty in a hydroxy polyoxyalkylene ester of a,fatacid.

forming fatty acid. In preparing the stabilizer composition, glycine Theinventionisapplicable for stabilizing any .and phosphoric acid aredissolved in the polyof the well-known fatty materials normallysuboxyethylene fatty ester, either with such ester in liquid form orwith the glycine and phosphoric acid in solution in a suitable mutualsolvent such as glycerine. The concentration of glycine and phosphoricacid in the ester solution can be varied as desired up to the limit ofsolubility. The stabilizer composition is then incorporated in the fattymaterial to be stabilized, with best results being obtained byincorporation at a temperature of 40-95 C. and more desirably at 5090C., temperatures above 95 C. being less desirable because of impairmentof the effectiveness of stabilization. The glycine and phosphoric acidprovide effective stabilization at concentrations of each of from0.00005% to 0.02% by weight based on the total composition weight.Larger amounts of glycine and phosphoric acid can be employed ifdesired, with amounts as high as 0.5% or higher of each of suchmaterials being suitable. Best results are obtained with the phosphoricacid present in an amount not greater than twice the weight of glycine,although larger proportions of glycine can be' used without adverseeffect. The amount of hydroxy polyoxyalkylene fatty acid ester can bevaried but is desirably present in an amount not greater than 5% byweight of the total weight of the stabilized fatty composition. In thepreferred triglyceride compositions, the fatty triglycerides are presentin an amount equal to at least 85% of the total composition weight.

The glycine and phosphoric acid are desirably employed in the form ofthe free acids. Materials furnishing glycine or phosphoric acid in thefatty composition can be employed, however, and are within the scope ofthe invention. Thus, for example, the phosphoric acid can be furnishedby a salt of phosphoric acid such as sodium phosphate, and the glycinecan be added hydrolysate within the scope of the invention.

The development of oxidative rancidity is usually evaluated by analysisof the peroxide content of a fatty composition, a peroxide value of 20millimols of peroxide per kilogram of fatty composition usually beingconsidered the maximum permissible value for commercial use. Thestability of fatty compositions is evaluated by the accelerated ActiveOxygen Method (AOM) wherein a sample of the composition being evaluatedis heated on a steam bath at a temperature of 96 C. with air bubblingthrough the sample and the time necessary for attaining a peroxide valueof 20 is determined by periodic analysis of the peroxide content andsonsidered the measure of stability.

The following specific examples illustrate certain preferred embommentsof the invention, it being understood that such examples areillustrative and are not intended to limit the scope of the inventionunless otherwise specifically indicated.

Example 1 A solution of i% by Weight of glycine and 4% by weight ofphosphoric acid in glycerol was mixed with hydroxy 40 oxyethylenemonostearate in an amount sufficient to give a solution of 0.02% byweight of each of the glycine and phosphoric acid in the monostearate.The resulting solution was stirred into oleic acid in an amount of 1.5%by weight of the glycine-phosphoric acid-monostearate composition basedon the weight of oleic acid, at a temperature of approximately 60 C. Thestabilized fatty composition obtained thereby was tested for stabilityunder the accelerated AOM test conditions and it was found that thestability of the oleic acid with respect to the time necessary to reacha peroxide value of 20 had been increased 60% over the untreated controlsample.

Example 2 A stabilized lard composition containing 0.0003% by weight ofglycine, 0.0003% by weight of phosphoric acid, and 1.5% by weight ofhydroxy-40-oxyethylene monostearate was evaluated by the AOM acceleratedtest. The stabilized composition required 29 hours to reach a peroxidevalue of 20 as compared to '7 hours for unstabilized lard.

Example 3 A partially hydrogenated cottonseed oil shortening wasstabilized by admixing therewith 1.5% by weight of a solution of 0.02%by weight of glycine and 0.02% by weight of phosphoric acid inhydroxy-40-oxyethylene monostearate. The AOM stability of the shorteningwas increased 40% by such stabilization.

Similar results are obtained with other hydroxy polyalkylene fatty acidesters, with other fatty materials and with varying concentrations ofglycine and phosphoric acid, and it will be understood that variationsand modifications can be effected within the spirit and. scope of theinvention as described hereinabove and defined in the appended claims.

I claim:

1. A fatty composition consisting predominantly of fatty materialnormally subject to oxidation and having incorporated in said fattymaterial a solution of glycine and phosphoric acid in a hydroxypolyalkylene oxide ester of a fatforming fatty acid.

2. A normally solid fat having incorporated therein a solution ofglycine and. phosphoric acid in a hydroxy polyoxyethylene ester of afatforming fatty acid.

3. A fatty oil having incorporated therein a solution of glycine and.phosphoric acid in a hydroxy polyoxyethylene ester of a fat-formingfatty acid.

4. A fatty compos'tion consisting predominantly of fatty triglyceridesand having dispersed therein a minor amount of a solution of glycine andphosphoric acid in a hydroxy polyoxyethylene ester of a fat-formingfatty acid.

5. A fatty triglyceride composition having incorporated therein asolution of glycine and phosphoric acid in a hydroxy polyoxyethyleneester of a fatty acid having at least 12 carbon atoms in the fatty acidmolecule, said glycine and said phosphoric acid each being present in anamount of not more than about 0.02% by weight based on the total weightof said composition, said phosphoric acid being present in an amount notgreater than twice the weight of said glycine.

6. A fatty composition comprising at least by weight of fattytriglycerides, from 0.00005% to 0.02% by weight of glycine, and from0.0005 to 0.02% by weight of phosphoric acid, all based on the totalcomposition weight, said glycine and. phosphoric acid being present insolution in a hydroxy polyoxyethylene ester of a fatty acid having atleast 12 carbon atoms in the fatty acid molecule.

'7. A shortening having incorporated therein a solution of glycine andphosphoric acid in a hydroxy polyoxyethylene ester of a fat-formingfatty acid.

8. A stabilizer composition suitable for incorporation in fatty materialnormally subject to 5 oxidation, said composition comprising asolumolecule, said phosphoric acid being present in tion of glycine andphosphoric acid in a, hydroxy an amount not greater than twice theweight of polyalkylene oxide ester of a fat-forming fatty said glycine.

acid.

9. A stabilizer for fatty material comprising 5 References Cited in e fiOf this Patent a solution of glycine and phosphoric acid in a UNITEDSTATES PATENTS hydroxy polyoxyethylene ester of a fatty acid Number NameDate having at least 12 carbon atoms 1n the fatty acid 2,511,804 HanJune 13, 1950 molecule.

10. A stabilizer for fatty material comprising 10 2535910 Fonyo 1950 asolution of glycine and phosphoric acid in a OTHER REFERENCES hydroxypolyoxyethylene ester of a fatty acid Chem Abs; 40 (1945), 5

having at least 12 carbon atoms in the fatty acid

1. A FATTY COMPOSITION CONSISTING PREOMINANTLY OF FATTY MATERIALNORMALLY SUBJECTED TO OXIDATION AND HAVING INCORPORATED IN SAID FATTYMATERIAL A SOLUTION OF GLYCINE AND PHOSPHORIC ACID IN A HYDROXYPOLYALKYLENE OXIDE ESTER OF A FATFORMING FATTY ACID.